/*
 * Copyright 2012 The Netty Project
 *
 * The Netty Project licenses this file to you under the Apache License,
 * version 2.0 (the "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at:
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */
package io.netty.channel;

/**
 * {@link SingleThreadEventLoop} which is used to handle OIO {@link Channel}'s.
 * So in general there will be one {@link ThreadPerChannelEventLoop} per
 * {@link Channel}.
 *
 */
public class ThreadPerChannelEventLoop extends SingleThreadEventLoop
{

    private final ThreadPerChannelEventLoopGroup parent;

    private Channel ch;

    public ThreadPerChannelEventLoop(ThreadPerChannelEventLoopGroup parent)
    {
        super(parent, parent.executor, true);
        this.parent = parent;
    }

    @Override
    public ChannelFuture register(ChannelPromise promise)
    {
        return super.register(promise).addListener(new ChannelFutureListener()
        {
            @Override
            public void operationComplete(ChannelFuture future) throws Exception
            {
                if (future.isSuccess())
                {
                    ch = future.channel();
                }
                else
                {
                    deregister();
                }
            }
        });
    }

    @Deprecated
    @Override
    public ChannelFuture register(Channel channel, ChannelPromise promise)
    {
        return super.register(channel, promise)
                .addListener(new ChannelFutureListener()
                {
                    @Override
                    public void operationComplete(ChannelFuture future)
                            throws Exception
                    {
                        if (future.isSuccess())
                        {
                            ch = future.channel();
                        }
                        else
                        {
                            deregister();
                        }
                    }
                });
    }

    @Override
    protected void run()
    {
        for (;;)
        {
            Runnable task = takeTask();
            if (task != null)
            {
                task.run();
                updateLastExecutionTime();
            }

            Channel ch = this.ch;
            if (isShuttingDown())
            {
                if (ch != null)
                {
                    ch.unsafe().close(ch.unsafe().voidPromise());
                }
                if (confirmShutdown())
                {
                    break;
                }
            }
            else
            {
                if (ch != null)
                {
                    // Handle deregistration
                    if (!ch.isRegistered())
                    {
                        runAllTasks();
                        deregister();
                    }
                }
            }
        }
    }

    protected void deregister()
    {
        ch = null;
        parent.activeChildren.remove(this);
        parent.idleChildren.add(this);
    }
}
